In a small randomized within-subject test, how much worse is recall of a story heard at 2x speed than at normal speed?

Problem. Whether double-speed audio costs memory. Conditions. 40 Lebanese university students (aged 18 to 25, convenience sample), each heard two four-sentence stories of 23 seconds, one at normal speed and one at 2x (after a habituation to 2x words), in counterbalanced order, then played Minesweeper for 10 minutes before cued recall. Measured result. Participants recalled about half of the information overall; normal speed gave a 27% improvement in cued recall over time-compressed speech, statistically significant. Students also reported using compressed speech more than average and mostly judged it harmful. Failure modes. Participants admitted rehearsing during the filler game; mood, time of day and location were uncontrolled. Limitations. Very short material, one narrator, one compression ratio (2x), delayed recall only after 10 minutes, no comprehension test, no ideal-pace data; cannot say what a 10 to 20% faster read would do. The authors suggest faster speeds for revision rather than first exposure. Inference (labelled): this supports using a slower first-pass pace for facts viewers must retain, but does not locate a best words-per-minute figure. Version/date. Published 31 Mar 2026 (CC BY-NC-ND, so summary and short quotes only). Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: n = 40, 23-second stimuli, one compression ratio, convenience sample; the 27% figure is the authors' summary of cued-recall difference (I did not recompute it from raw scores). Not evidence about natural speaking rates between 120 and 190 wpm. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

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